Heat Pump Panel Check — Washington

In Washington, a whole-home air-source heat pump typically costs $5,000–$14,000 installed, depending on home size, system type, and contractor. Cold-climate models for zones like Zone 4C cost more but deliver lower operating costs. Combined rebates of up to $9,200 (HEEHRA + state programs) can offset a significant portion of installed cost.

Yes — Washington has launched its HEEHRA program. Income-qualified households (under 80% AMI) can receive up to $8,000 for a qualifying heat pump. Moderate-income households (80–150% AMI) may receive up to $4,000. Washington State HEEHRA is active and accepting applications. Administered by the WA Department of Commerce. Income-qualified households (≤ 150% AMI): $8,000 for heat pumps (< 80% AMI), $4,000 (80–150% AMI). Must use a participating contractor. Point-of-sale — no tax liability required. Funds are first-come-first-served until depleted.

Washington falls in IECC 2021 Zone 4C — Mixed-Marine. Typical winter design temperatures are 28°F to 37°F. Marine-influenced winters are mild and damp. Standard ASHP is efficient; cold-climate models add buffer for occasional cold snaps. Sizing requires a Manual J load calculation — but as a rough rule, allow 20–30 BTU/h per square foot for older homes in Washington.

Not necessarily. Most 200A panels in Washington have headroom for a heat pump under the NEC 220.82 Optional Method — which accounts for diversity of loads rather than peak simultaneous demand. A 100A panel is more likely to require an upgrade, especially if you also have an EV charger or electric range. Our free audit calculates your exact available capacity in 3 minutes using the same method your electrician would use.